As many as 70% of patients with SIRS, sepsis, or MOF have either a polyneuropathy or myopathy [Musc Nerve 32: 140, 2005], but usually these disorders are overshadowed by more obvious conditions. [NEJM 348: 745, 2003]
Polyneuropathy is treated by prevention and tight glucose control – one study showed that glucose control can reduce the incidence by 44% [NEJM 345: 1359, 2001]. 50% of patients will recover completely, but can take months.
Myopathy presents as diffuse weakness, depressed DTRs, and mildly elevated CK levels [Curr Rheum Rep 4: 403, 2002]. It is more prevalent with longer term use of corticosteroids and neuromuscular blocking agent [Musc Nerve 32: 140, 2005, Curr Rheum Rep 4: 403, 2002]. There is no specific treatment, and recovery may take months. Beware respiratory insufficiency (cough, clearing secretions, and ventilation) – if PImax < 30 cm H20, the patient has severe respiratory muscle weakness and should be intubated. [Am Rev Res Dis 138: 867, 1988]
When critical illness-associated myopathy is a concern and paralysis is needed, cisatracurium may be the drug of choice – in a recent randomized controlled trial designed to study the use of paralysis in patients with ARDS, the use of cisatracurium was not associated with an increased risk of muscle weakness [Papazian L et al. N Engl J Med 363: 1107, 2010].